Primary abnormalities of the ocular surface epithelium may play a role in ocular surface diseases and problems, such as the "dry eye" syndromes, pseudopemphigoid, diabetes, and following chemical or thermal injury. However, since many of the conditions associated with ocular surface disease were believed to be secondary to other manifestations of the disease process (e.g., inadequate tear supply, exposure), relatively little information on the ocular surface epithelium itself has been accumulated. Our objectives, therefore, are: (1) to continue to identify the normal processes of glucose and glycogen metabolism, and of mucus production; (2) to relate these processes to the maintenance and proliferation of surface cells; (3) to create and evaluate surface abnormalities in experimental animals with the aim of relating specific metabolic to specific functional changes in the epithelium; (4) to use the methods and information learned above to define primary ocular surface disease in patients; and finally, (5) to investigate the efficacy of current and new therapeutic measures in ocular surface disease.